Spasmodic dysphonia

Abstract

Spasmodic Dysphonia is a focal laryngeal dystonia affecting intrinsic laryngeal muscles during speech. Many other voice disorders could mimic this situation and lead to diagnostic difficulties. Other focal distonias and neurological diseases may be associated, too. A teamwork including an otolaryngologist, neurologist and speech-language pathologist is essential when spasmodic disphonia is suspected. The precise aetiology still unknown and the pathophysiology, which have not been fully revealed, lead to difficulties in the search for effective treatment. There is no definitive treatment adopted. Although effectiveness of voice therapy has not yet been shown in true spasmodic dysphonia, one trial of voice therapy is recommended for rule out possible misdiagnosis as well as disable psychogenic factors. Surgical denervation has been performed since the 1970s, but long-term results have not been satisfactory. Denervation and reinnervation of recurrent laryngeal nerve and laryngoplastic techniques developed in recent years may hold promise but there are limited data regarding the long-term results while the number of patients who underwent those procedures was small. Botulinum toxin applications still continues to be a popular choice. Due to it’s temporary denervation, short duration of effect, requiring repetition, side effects such as breathy voice and swallowing difficulty, and risk of resistance, the necessity for development of more permanent treatment is still required.